#279 Interbody Cages with Wide Contact Area in Lateral Interbody Fusion – Biomechanics, Clinical and Radiological Features

General Session: Lumbar Therapies Motion Preservation

Presented by: L. Pimenta

Author(s):

L. Pimenta (1), (2)
R. Jensen (1)
L. Marchi (1)
L. Oliveira (1)
C. Castro (1)
E. Coutinho (1)
T. Coutinho (1)
R. Amaral (1)

(1) Instituto de Patologia da Coluna, São Paulo, Brazil
(2) UCSD, Neurosurgery, San Diego, CA, USA

Abstract

Introduction: The influence of the cage width on indexes of surgical goals and complications is yet unknown on lateral interbody fusion. In this work we present a biomechanical study and preliminary clinical and radiological results.

Methods: Biomechanical study: 8× L2-3 FSU specimens/group. Test conditions: intact; bilateral pedicle screws (PS); interbody fusion at L2-3 with unilateral PS or with bilateral PS (with 18mm, 26mm or 11mm antero-posterior dimension cages). Prospective clinical study: Seventy-eight patients (106 lumbar levels; mean 60.9y/o and BMI27.9) underwent transpsoas interbody fusion with 26mm cages. Clinical outcomes were assessed by ODI and VAS. Segmental/global lumbar lordosis, subsidence and complications were assessed. Comparison with previous studies on 18mm and 22mm cages were carried out.

Results: Biomechanical studies revealed that standalone 26mm cage has greater stability than 18mm cage with unilateral PS and 11mm cage with bilateral PS. 18mm cage with unilateral PS stability greater than 11mm cage with bilateral PS. VAS and ODI scores improved with an early and lasting pattern. Subsidence occurred in 7% of treated levels, equal to the 22mm cage results (10%), and lower than the 18mm cage results (30%) (p< 0.01). Psoas weakness occurred in 6.7% of cases, psoas hematoma-3.3%, tight pain-6.7%, and 5% needed revision due to lasting stenosis. Although overall all patients had gain in segmental lumbar lordosis, wider cage groups gain were higher than for standard group (7%-18mm, 17%-22mm and 19%-26mm p= 0.0004).

Conclusions: Wider cages are biomechanically stable and have a significant impact on avoiding cage subsidence occurrence, while was not observed increment on complications.

Biomechanical results